Many conventional jet aircraft use a tricycle-type landing gear configuration. This configuration typically includes left and right main gears extending downwardly from the main wing, and a nose gear extending downwardly from a forward portion of the fuselage. For takeoff, such aircraft generally build up airspeed while on the nose gear and main gears, and then rotate about the main gears to a nose-up position for lift off. This rotation causes the tail of the aircraft to move downwardly toward the runway surface. Although the tail rarely contacts the runway, a tail skid or other protective device is often provided at the contact point to prevent fuselage damage in the unlikely event that contact does occur.
During landing, aircraft with tricycle-type landing gear configurations typically approach the runway in a slightly nose-up attitude that is somewhat less inclined than at takeoff. Upon touchdown, the downward momentum of the aircraft causes the main gears to compress, again bringing the tail of the aircraft into relatively close proximity to the surface of the runway. When the main gears are compressed, however, the tail skid may not be in a position to prevent fuselage damage if the aircraft over-rotates during landing. For this reason, the nose-up attitude of conventional aircraft is generally limited during the landing approach to provide an acceptable margin between the tail of the aircraft and the runway surface at touchdown.
Some jet aircraft that rotate about main gears for takeoff include movable tail skids. Such aircraft include, for example, the Boeing 757, 767, and 777 families of aircraft. On these aircraft, the tail skids are typically extended away from the fuselage for both take off and landing, and retracted toward the fuselage to reduce aerodynamic drag during flight. These tail skid are configured to absorb energy from incidental runway contact only in the extended position.
In many situations, it may be advantageous to reduce landing speeds of aircraft having tricycle-type landing gear configurations. For example, certain commercial aircraft operators may desire lower approach speeds for service to selected airports having shorter runways. In addition, certain operators may desire increased payload weights. Lower approach speeds and increased payload weights, however, often dictate that the aircraft assume a higher nose-up attitude during the approach. As explained above, however, this nose-up attitude may be limited to avoid fuselage damage from incidental runway contact.